| Parameter |
Value |
| Designation |
C/1983 R1 (Shoemaker) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1983-11-23T19:05:28.720320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
117 |
| NEO |
- |
| M1 |
5.800 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1983-12-05.0000000 |
| e |
1.00019923 |
| q (au) |
3.344912 |
| a (au) |
-16789.101324 |
| i (deg) |
137.597258 |
| Ω (om, deg) |
164.683890 |
| ω (w, deg) |
176.039037 |
| M (ma, deg) |
0.000005 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.970 + 5.968\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.970 |
| n |
5.968 |
| gf |
1.000 |
| gb |
-0.719 |
| k |
0.800 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
11:53:23.10 |
-21:02:51.7 |
HIP 57771 |
35.79 |
| 2026-05-12 12:00 |
11:53:21.98 |
-21:02:36.6 |
HIP 57771 |
35.51 |
| 2026-05-13 00:00 |
11:53:20.87 |
-21:02:21.5 |
HIP 57771 |
35.24 |
| 2026-05-13 12:00 |
11:53:19.77 |
-21:02:06.4 |
HIP 57771 |
34.97 |
| 2026-05-14 00:00 |
11:53:18.68 |
-21:01:51.4 |
HIP 57771 |
34.70 |
| 2026-05-14 12:00 |
11:53:17.60 |
-21:01:36.3 |
HIP 57771 |
34.44 |
| 2026-05-15 00:00 |
11:53:16.54 |
-21:01:21.3 |
HIP 57771 |
34.18 |
| 2026-05-15 12:00 |
11:53:15.49 |
-21:01:06.3 |
HIP 57771 |
33.93 |
| 2026-05-16 00:00 |
11:53:14.46 |
-21:00:51.4 |
HIP 57771 |
33.68 |
| 2026-05-16 12:00 |
11:53:13.43 |
-21:00:36.4 |
HIP 57771 |
33.44 |
| 2026-05-17 00:00 |
11:53:12.42 |
-21:00:21.5 |
HIP 57771 |
33.20 |
| 2026-05-17 12:00 |
11:53:11.43 |
-21:00:06.6 |
HIP 57771 |
32.97 |
| 2026-05-18 00:00 |
11:53:10.44 |
-20:59:51.8 |
HIP 57771 |
32.74 |
| 2026-05-18 12:00 |
11:53:09.47 |
-20:59:37.0 |
HIP 57771 |
32.52 |
| 2026-05-19 00:00 |
11:53:08.52 |
-20:59:22.2 |
HIP 57771 |
32.30 |
| 2026-05-19 12:00 |
11:53:07.57 |
-20:59:07.4 |
HIP 57771 |
32.09 |
| 2026-05-20 00:00 |
11:53:06.64 |
-20:58:52.7 |
HIP 57771 |
31.88 |
| 2026-05-20 12:00 |
11:53:05.73 |
-20:58:38.0 |
HIP 57771 |
31.68 |
| 2026-05-21 00:00 |
11:53:04.82 |
-20:58:23.4 |
HIP 57771 |
31.48 |
| 2026-05-21 12:00 |
11:53:03.94 |
-20:58:08.8 |
HIP 57771 |
31.29 |
| 2026-05-22 00:00 |
11:53:03.06 |
-20:57:54.2 |
HIP 57771 |
31.10 |
| 2026-05-22 12:00 |
11:53:02.20 |
-20:57:39.7 |
HIP 57771 |
30.92 |
| 2026-05-23 00:00 |
11:53:01.35 |
-20:57:25.2 |
HIP 57771 |
30.75 |
| 2026-05-23 12:00 |
11:53:00.52 |
-20:57:10.8 |
HIP 57771 |
30.58 |
| 2026-05-24 00:00 |
11:52:59.69 |
-20:56:56.4 |
HIP 57771 |
30.41 |
| 2026-05-24 12:00 |
11:52:58.89 |
-20:56:42.0 |
HIP 57771 |
30.25 |
| 2026-05-25 00:00 |
11:52:58.10 |
-20:56:27.7 |
HIP 57771 |
30.10 |
| 2026-05-25 12:00 |
11:52:57.32 |
-20:56:13.5 |
HIP 57771 |
29.95 |
| 2026-05-26 00:00 |
11:52:56.55 |
-20:55:59.3 |
HIP 57771 |
29.80 |
| 2026-05-26 12:00 |
11:52:55.80 |
-20:55:45.1 |
HIP 57771 |
29.66 |
| 2026-05-27 00:00 |
11:52:55.06 |
-20:55:31.0 |
HIP 57771 |
29.53 |
| 2026-05-27 12:00 |
11:52:54.34 |
-20:55:16.9 |
HIP 57771 |
29.40 |
| 2026-05-28 00:00 |
11:52:53.63 |
-20:55:02.9 |
HIP 57771 |
29.28 |
| 2026-05-28 12:00 |
11:52:52.94 |
-20:54:48.9 |
HIP 57771 |
29.16 |
| 2026-05-29 00:00 |
11:52:52.26 |
-20:54:35.0 |
HIP 57771 |
29.05 |
| 2026-05-29 12:00 |
11:52:51.59 |
-20:54:21.1 |
HIP 57771 |
28.94 |
| 2026-05-30 00:00 |
11:52:50.94 |
-20:54:07.3 |
HIP 57771 |
28.84 |
| 2026-05-30 12:00 |
11:52:50.30 |
-20:53:53.5 |
HIP 57771 |
28.75 |
| 2026-05-31 00:00 |
11:52:49.68 |
-20:53:39.8 |
HIP 57771 |
28.66 |
| 2026-05-31 12:00 |
11:52:49.07 |
-20:53:26.2 |
HIP 57771 |
28.57 |
| 2026-06-01 00:00 |
11:52:48.48 |
-20:53:12.6 |
HIP 57771 |
28.49 |
| 2026-06-01 12:00 |
11:52:47.90 |
-20:52:59.1 |
HIP 57771 |
28.42 |
| 2026-06-02 00:00 |
11:52:47.33 |
-20:52:45.6 |
HIP 57771 |
28.35 |